Dynamoelectric machines such as motors and generators and other rotating machines such as gears, pumps, compressors and bearing systems including rolling element bearings and hydrodynamic bearings are widely employed in industrial, military and commercial facilities. These machines are relied upon to operate with minimal attention and provide for long, reliable operation. Many facilities operate several hundred or even thousands of such machines concurrently, several of which are integrated into a large interdependent process or system. Several machines, such as aircraft, land vehicles, and marine systems employ sensors to obtain measurements related to critical parameters of fluid that operates within the machines. Like most machinery, at least a small percentage of such equipment is prone to failure. Some of these failures can be attributed to loss of lubrication, incorrect lubrication, lubrication breakdown, or lubrication contamination.
Depending on the application, failure of a machine in service can possibly lead to system or process latency, inconvenience, material scrap, machinery damage, hazardous material cleanup, and even a dangerous situation. Thus, it is desirable to diagnose machinery for possible failure or faults early in order to take preventive action and avoid such problems. Absent special monitoring for certain lubrication problems, a problem may have an insidious effect in that although only a minor problem at the outset, the problem could become serious if not detected. For example, bearing problems due to inadequate lubrication, lubrication contamination or other causes may not become apparent until significant damage has occurred.
Proper lubrication facilitates extension of machinery life. For example, when motor lubricant is continuously exposed to high temperatures, high speeds, stress or loads, and/or an oxidizing environment, the lubricant will deteriorate and lose its lubricating effectiveness. The loss of lubricating effectiveness will affect two crucial functions of a lubrication system, namely: (1) to reduce friction; and (2) to remove heat. Continued operation of such a degraded system may result in even greater heat generation, further exacerbating system degradation, eventually leading to substantial machinery damage and ultimately catastrophic failure.
To protect the system (e.g., a motor, a pump, an engine, a gearbox . . . ), the lubricant should be changed in a timely fashion. However, a balance must be struck—on one hand it is undesirable to replace an adequate lubricant but on the other hand it is desired to replace a lubricant that is in its initial stages of breakdown or contamination prior to occurrence of equipment damage. Moreover, in some circumstances, e.g., during critical periods of operation, it may be infeasible or impossible to replace a lubricant even if it becomes known that a replacement is necessary.
Measurements relating to machine fluids obtained from sensing elements and/or a laboratory process are then utilized to prevent substantial degradation of the machine fluids, and thus prevent damage to the machine. Even if such measurements are taken at regular intervals, however, a maintenance engineer is still required to effectuate maintenance measures (e.g., fluid addition, fluid replacement, addition of anti-oxidants . . . ). Particular machinery requiring fluid maintenance can be located at positions on the machinery that is difficult to reach and therefore requires a significant amount of the maintenance engineer's time to perform such maintenance. Furthermore, the maintenance engineer is prone to human error and can add incorrect fluids and/or fluid additives to a particular machine or machine component, as well as provide the machine or machine component with an over-abundance of fluid. Access to some machines for fluid service may require access to hazardous areas by maintenance personnel or may require machinery or process shutdown to insure worker safety. The additional risk of worker safety and possible machinery shutdown for lubricant service must be minimized to provide ultimate protection of maintenance staff and insure continued operation of process machines. These risks, operating cost, and other potential maintenance errors can result in accelerated failure of the machine and/or machine component, increased worker risk of safety and reduced economic performance of the organization.
Conventional systems and/or methods for in situ measurement and analysis of fluids in machinery only detect one or a very small number of fluid parameters. Moreover, there does not exist a way to collect a wide variety of fluid parameters from various types of sensors in order to get a complete picture of the condition of the fluid in real time. For example, one sensor may be able to detect a parameter and determine that it is not ideal, but generally, the sensor does not know why that is so, much less what remedial actions (if any) could be taken to mitigate a harmful condition. Further, certain types of contaminants within a fluid cannot easily or inexpensively be detected. Lastly, knowing what is the condition of the lubricant and the possible reasons permits determining whether it is safe to continue operating the equipment or if an immediate equipment shutdown is warranted.
For example, metal wear during operation can contaminate a fluid with metal particles, which can be a problem not easily detectable in a useful way. Detecting metal in fluids today is either performed by extracting a sample and performing a laboratory analysis. Alternatively, there are a few commercial products that employ optical methods to detect particles. The optical methods are costly, large, heavy, and do not determine the particle type. They only detect the particle size and number of particles. Another difficulty often arisen because occasionally entrapped air bubbles may also be classified as a particle by optical sensors.
In addition, there exist many difficulties for a multiple sensor system to communicate with other components. Hence, there is a need for an effective wireless solution for wireless and/or satellite communication. One difficulty associated with sensors that are not wired is providing power to the sensor. Due to a limited life, batteries are often not a feasible solution. The remaining life of batteries are typically difficult to determine raising the likelihood of unexpected loss of sensor function, battery replacement requires labor and machinery access, and replacement batteries represent a non-trivial maintenance and logistics burden including the safe, environmentally conscious disposal of depleted batteries. Today there are some energy harvesting techniques that extract, convert, and store ambient energy from the environment. However, none of these techniques exploit the characteristics of the fluid itself. Lastly, sensors typically employed are passive devices and do not change fluid or sensor conditions in the vicinity of the sensor elements.
In view of at least the above, there exists a strong need in the art for a system and/or methodology facilitating improved real-time in situ measurement and analysis of parameters relating to fluid in machinery, and a system and/or methodology for maintaining such fluids.